Kabul - An accidental explosion in an arms depot shook central Kabul on Thursday before Afghan officials moved quickly to allay fears of an attack on the city that has often been targeted by militants.
The loud blast erupted close to the Nato's International Security Assistance Force (ISAF) headquarters and in an area of the capital that houses many embassies and international institutions.
ISAF confirmed that the blast occurred outside their headquarters, while the US embassy sounded its emergency "duck and cover" sirens to warn employees to seek shelter.
"It was an accident, not an enemy act," Lutfullah Mashal, an official from the national directorate of security (NDS) intelligence agency, told AFP.
"The blast happened in a depot for unexploded ordinance. It was totally an accident. There are no reported casualties, but there are some damages."
An NDS spokesperson told local television that the blast happened in an NDS depot that contained explosives, unexploded bombs and suicide vests seized from insurgents.
Taliban take responsibility
The interior ministry also confirmed the explosion was an accident.
The blast came the day after a Taliban suicide bomber detonated an explosives-laden vehicle near a Nato military convoy entering Kabul airport, killing himself but causing no other deaths or injuries.
The airport houses another Nato base as well as operating civilian flights to cities including Dubai, New Delhi and Istanbul. Flights were delayed only briefly after the bomb exploded.
The Taliban, who regularly exaggerate casualty numbers, claimed responsibility via their main Twitter account for that attack, saying ten soldiers had been killed or injured.
Kabul has seen a recent drop in insurgent attacks after a series of high-profile strikes earlier this year, with the NDS claiming to have foiled several plots to launch complex strikes involving truck bombs and suicide gunmen.
A series of attacks earlier this year targeted foreign compounds, the Supreme Court, the airport and the presidential palace in the city.